If I delete all my mail on my iPhone will it clear some space?

I have used almost all of my space on my iPhone and I have deleted alot of things but i still have only 2gb left to use. I have like 3, 000 emails that I haven't deleted. Will that clear some space?

No, they get stored on your email providers server, not your iPhone.

No. How about you try this:
Email a lot of your photos to yourself, and delete them off of your phone, that way, when you need them, it won't take up space in your phone. Instead, you go to your email and open them. It's worth a try. Also, try deleting apps you rarely use, since they take up a lot of space aswell.